diff --git a/lib/fse.c b/lib/fse.c
index e07b951cd..2861fd9f1 100644
--- a/lib/fse.c
+++ b/lib/fse.c
@@ -542,7 +542,7 @@ unsigned FSE_optimalTableLog(unsigned maxTableLog, size_t srcSize, unsigned maxS
     U32 tableLog = maxTableLog;
     if (tableLog==0) tableLog = FSE_DEFAULT_TABLELOG;
     if ((FSE_highbit32((U32)(srcSize - 1)) - 2) < tableLog) tableLog = FSE_highbit32((U32)(srcSize - 1)) - 2;   /* Accuracy can be reduced */
-    if ((FSE_highbit32(maxSymbolValue+1)+1) > tableLog) tableLog = FSE_highbit32(maxSymbolValue+1)+1;   /* Need a minimum to safely represent all symbol values */
+    if ((FSE_highbit32(maxSymbolValue)+2) > tableLog) tableLog = FSE_highbit32(maxSymbolValue)+2;   /* Need a minimum to safely represent all symbol values */
     if (tableLog < FSE_MIN_TABLELOG) tableLog = FSE_MIN_TABLELOG;
     if (tableLog > FSE_MAX_TABLELOG) tableLog = FSE_MAX_TABLELOG;
     return tableLog;